In various flat panel displays, Organic Light Emitting Display (OLED for short) has advantages such as a wide viewing angle, a good color contrast effect, a fast response time, and low costs, and therefore is expected to become the mainstream of a next generation of flat panel displays.
OLED has a plurality of types, for example, a top-emitting type, a bottom-emitting type, and a dual-sides emitting type. In order to maintain a required storage capacitor, an area large enough needs to be reserved. For the bottom-emitting display or the dual-sides emitting display, arrangement of a storage capacitor leads to problems of a very small effective light emitting region and a relatively small aperture ratio. Besides, if an additional touch sensing element is to be designed in an OLED, a manufacturing process becomes more complex, and an aperture ratio becomes even smaller.